Efficacy of doripenem in the treatment of Pseudomonas aeruginosa experimental pneumonia versus imipenem and meropenem

Results: Mean pulmonary bacterial loads were 3.17+0.53, 3.42+0.61 and 2.75+0.59 log10 cfu/g for imipenem, doripenem (0.5 g three times daily) and meropenem, respectively, compared with 7.57+0.99 cfu/g for control animals. At a higher dose (1 g three times daily), doripenem showed significantly better efficacy (2.70+0.65 log10 cfu/g) than the standard regimen of doripenem. Sterilization of spleen cultures was achieved with standard regimens of imipenem (1 g three times daily) and a higher dose of doripenem. Conclusions: In this model of P. aeruginosa pneumonia, doripenem had an efficacy equivalent to that of meropenem and imipenem at a high dose of 1 g three times a day and lower efficacy at a standard dose (0.5 g three times daily) than the other two agents in terms of bacteria cultivated from spleens. Doripenem is a new drug that offers new therapeutic options, especially for difficult-to-treat infections such as pneumonia due to non-fermenting Gram-negative bacteria.